Pettersson, Maria

Abstract [en]

The aim of this thesis was to investigate if endocrine disruption related to the release of estrogenic and/or androgenic substances via sewage treatment plant and pulp mill effluents is significant in Swedish waters. Chemical analysis of bile fluid in combination with measurement of biomarkers was used for the evaluation of internal exposure and effects in fish.

Exposure to estrogenic substances was demonstrated by pronounced induction of the yolk protein precursor vitellogenin in fish exposed in cages downstream of a small domestic Swedish sewage treatment plant. Estrogenic substances identified in bile from the fish included the natural estrogens, the synthetic estrogen ethinylestradiol and some estrogenic phenols. The bile levels of estrogenic substances corresponded well with the plasma levels of vitellogenin. Significant concentrations of the estrogenic substances were also determined in the effluent water, and it was suggested that the level of ethinylestradiol was sufficient to explain a major part of the observed estrogenicity. Low or no induction of vitellogenin was observed in fish when exposed to final effluent from two modern Swedish sewage treatment plants, and it was concluded that a well functioning biological treatment reduces the amounts of estrogenic substances from the sewage water and that slow sand filtration contributes to further reduction. A field survey along the Baltic Sea coast revealed no signs of estrogenic or androgenic disruption in recipients of sewage treatment plants or pulp mills. This is likely due to efficient water treatment and high dilution rates in the recipients. Endocrine disruption might still be of local concern in receiving waters of less treated effluents that have low dilution rates.

A sensitive method for determination of estrogenic substances in water was developed, which will make it possible to establish bioconcentration relationships between water and fish, and dose-response relationships with biomarkers in fish.

Berg, A.H.

Olsson, P.-E.

Förlin, L.

Abstract [en]

Environmental oestrogens are natural or synthetic substances present in the environment, which imitate the effects of endogenous oestrogen. Oestrogenic substances were identified by gas chromatography/mass spectrometry in effluent water from a Swedish sewage treatment works receiving mainly domestic wastewater. Substances found include the synthetic oestrogen used in contraceptives 17 alpha-ethinyloestradiol (4.5 ng l(-1)), the natural oestrogens oestrone (5.8 ng l(-1)) and 17 beta-oestradiol (1.1 ng l(-1)), and the weaker non-steroidal oestrogens 4-nonylphenol (840 ng l(-1)) and bisphenol A (490 ng l(-1)). Ethinyloestradiol exceeded levels shown to be oestrogenic to fish by 45 times. The oestrogenicity of the effluent water was investigated by introducing juvenile rainbow trout (Oncorhynchus mykiss) in cages downstream of the sewage treatment works. After 2 weeks, all oestrogens indicated were present in the bile of the fish, and the oestrogen inducible protein, vitellogenin, was found in large amounts in the plasma (1.5 mg ml(-1)), as determined by enzyme-linked immunosorbent assay and Western blotting. Thus, a widely used synthetic oestrogen affects the endocrine systems of fish exposed to sewage effluent water.

Abstract [en]

Endocrine disrupting effects on fish associated with sewage treatment effluents have been demonstrated in several studies. To investigate if the effluents from two modem Swedish sewage treatment plants contained estrogenic substances, juvenile rainbow trout were exposed to sewage water before and after the last treatment step which is a sand filter. As a biomarker for estrogenic effect, vitellogenin was analysed in the blood plasma of the exposed fish. To identify substances possibly responsible for the effect, bile fluid from the exposed fish were analysed with GUMS. Elevated levels of vitellogenin were only seen in the fish exposed at one of the sewage treatment plants, the one with shorter residence time in the biological treatment steps, which suggests that the residence time is of importance for the ability to reduce the amount of estrogenic substances in the sewage water. The highest elevation of vitellogenin was seen in the fish exposed to water before the sand filter, which indicates that the sand filter contributes to further reduction of estrogenic substances in the sewage water. In bile from the same group of fish, considerably higher concentrations of estrone, bisphenol A and 4-nonylphenol (4.0 mu g/g bile, 23 mu g/g bile and 24 mu g/g bile, respectively) were observed compared to bile from control fish (< 0.04 mu g/g bile, 0.21 mu g/g bile, and 3.5 mu g/g bile, respectively). The more potent steroidal estrogens were suggested to be major contributors to the observed estrogenic effect, although xenoestrogens were detected at higher concentrations in the bile fluid.